Which trees are best to plant to help combat global warming?
--Tim C., Perrineville, NJ
Trees are important tools in the fight to stave off global
warming, because they absorb and store the key greenhouse
by our cars and power plants, carbon dioxide (CO2), before
it has a chance to reach the upper atmosphere where it
trap heat around the Earth’s surface.
While all living plant matter absorbs CO2 as part of photosynthesis,
trees process significantly more than smaller plants due
to their large size and extensive root structures.
According to the U.S. Department of Energy (DOE), tree species
that grow quickly and live long are ideal carbon sinks. Unfortunately,
these two attributes are usually mutually exclusive. Given
the choice, foresters interested in maximizing the absorption
storage of CO2 (known as “carbon sequestration”)
usually favor younger trees that grow more quickly than their
older cohorts. However, slower-growing trees can store much more
carbon over their significantly longer lives.
Scientists are busy studying the carbon sequestration potential
of different types of trees in various parts of the U.S.,
including Eucalyptus in Hawai‘i, loblolly pine in the Southeast,
bottomland hardwoods in Mississippi, and poplars in the Great
There are literally dozens of tree species that could be planted
depending upon location, climate, and soils,” said Stan
Wullschleger, a researcher at Tennessee’s Oak Ridge National
Laboratory who specializes in the physiological response of plants
to global climate change.
Dave Nowak, a researcher at the U.S. Forest Service’s Northern
Research Station in Syracuse, New York has studied the use of
trees for carbon sequestration in urban settings across the United
States. A 2002 study he co-authored lists the Common Horse-chestnut,
Black Walnut, American Sweetgum, Ponderosa Pine, Red Pine, White
Pine, London Plane, Hispaniolan Pine, Douglas Fir, Scarlet Oak,
Red Oak, Virginia Live Oak, and Bald Cypress as examples of trees
especially good at absorbing and storing CO2. Nowak advises urban
land managers to avoid trees that require a lot of maintenance,
as the burning of fossil fuels to power equipment like trucks
and chainsaws will only erase the carbon absorption gains otherwise
Ultimately, trees of any shape, size or genetic origin help
absorb CO2. Most scientists agree that the least expensive
easiest way for individuals to help offset the CO2 that they
generate in their everyday lives is to plant trees. Those
who wish to help larger tree planting efforts can donate
or time to the National Arbor Day Foundation or to the Tree
www.americanforests.org; www.arborday.org; www.treecanada.ca.
Submit questions to firstname.lastname@example.org.